Archived posting to the Leica Users Group, 2001/04/02
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Thank you, Erwin. I think there is some misunderstanding. While we have differed and probably still do as to the comparative merits of the 50mm Summicrons, I agree with you that the lens designer strives for maximum contrast and resolution within the parameters of the possible. The possible relates to projected selling price, available glasses and their cost, physical manufacturing construction costs and the concomitant maintenance of design tolerances, etc. But the fact of the matter is that when Leitz lens designers recomputed the 50/2 Summicron in 1979 (11819), they sought and achieved enhanced contrast and the result was that that lens, as you have written, does not match the resolution of the DR. As to your two other points, I am in complete agreement. First, With the exception of a short period 25 years ago when I was using Agfachrome 100 for the speed, for my color photography I have used nothing but Kodachrome 25 since its introduction and its predecessors before that. And I have been using K 64 for the last three or four years and just recently began with K200. I have not the testing capabilities that you can deploy, but what these films produce in the final image (slide) is quite remarkable. The trade-off in narrow latitude and the need for very exact exposure for those portions of the image that are most important are small prices to pay for the result. Second, I have always assumed that Leitz filters provided me with perfect optical glass and that their mounts provided me with an optical plane perfectly perpendicular to the lens axis. I have not seen perceptible degradation of the image unless the scene included light sources or reflected light in which case I'm going to have flare in any event. I have frequently left UV filters on my lenses for protection from dust, moisture or my dirty fingers! Kudos on your book. Seth Rosner